Composite plate, especially for raised floors

Abstract

With the composite plates for raised floors which are supported at their four corners and consist of a shell with open top and manufactured of tension-resistant material as well as a filling of pressure-resistant material, for instance anhydrite, when the plate is under stress there is a higher deflection at the plate border than in the middle of the plate, which is undesirable. In order to substantially equalize the bearing strength of composite plates of the above structural design in the border and the middle of the plate and to assure such plates against rupture at the border, a reinforcement which is practically plate-high is provided on the side wall of the shell, which is connected with the bottom plate of the shell. In addition or alternatively thereto the density and strength of the filling in the border area of the composite plate could also be increased at least twofold as compared with the rest of the area extending toward the middle of the plate.

It is claimed: 
     
       1. Composite plate, especially for raised floor plate constructions to be supported at the corners, comprising a shell having side walls and being open at the top, manufactured of tension-resistant material, a filling of pressure-resistant material, anchoring means in the shell for generating a binding effect between the filling and the shell, and reinforcing plate means connected to the shell, characterized in that the reinforcing plate means is provided on the side walls of the shell for increasing the thickness thereof so that it is at least twice the thickness of the bottom of the shell so that the bearing strength of the composite plate is substantially equalized in the border and the middle of the plate, whereby assurance is provided against rupture at the border. 
     
     
       2. Composite plate as in claim 1, in which the shell is made of one segment of a flat sheet metal plate by turning border strips upward between cutout corners and welding the contacting edges at the corners of the shell, characterized in that the border strips (21) of the flat sheet metal plate are folded back at least sufficiently to double the thickness of the shell side walls (6b), are bent upward and are welded to their contact edges (25). 
     
     
       3. Composite plate as in claim 1, characterized in that the reinforcing means is formed by reinforcing members fastened to the side walls of the shell. 
     
     
       4. Composite plate as in claim 1, characterized in that the shell is of two pieces and is manufactured of a bottom plate of sheet metal (7) provided with anchoring means (4) and also of reinforced side walls connected to the bottom plate, the wall thickness (S4) of the side walls being at least three times the thickness (S1) of the bottom plate (7). 
     
     
       5. Composite plate as in claim 4, characterized in that the borders (7a) of the bottom plate of sheet metal (7) are additionally deformed to increase the moment of resistance in the border area of the plate (10g). 
     
     
       6. Composite plate as in claim 3, characterized in that the reinforcing members for reinforcement of the shell side walls have a greater structural height in the middle areas between the corners of the shell, whereby said middle areas have a greater moment of resistance than those areas adjacent to the corners of the shell. 
     
     
       7. Composite plate as in claim 3, characterized in that the reinforcing members are formed of generally flat sheet material. 
     
     
       8. Composite plate as in claim 3, characterized in that the reinforcing members are angled members. 
     
     
       9. Composite plate as in claim 3, characterized in that the reinforcing members are fastened to the inside of the side walls. 
     
     
       10. Composite plate as in claim 3, characterized in that the reinforcing members are fastened to the outside of the side walls. 
     
     
       11. Composite plate as in claim 1, characterized in that the density and strength of the filling in the border area of the composite plate is at least twice as great as the density and strength of the filling in the remaining area extending toward the middle of the plate. 
     
     
       12. Composite plate, especially for raised floor plate constructions to be supported at the corners, comprising a shell which is open at the top, manufactured of tension-resistant material, a filling of pressure-resistant material, and also with anchoring means in the shell for generating a binding effect between the filling and the shell, characterized in that the density and strength of the filling in the border area of the composite plate in comparison with the remaining area extending toward the middle of the plate is such that it is at least twice as great by comparison so that the bearing strength of the composite plate is substantially equalized in the border and the middle of the plate, whereby assurance is provided against rupture at the border.